<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>JS Set</title>
</head>
<body>
<p>迭代 Set 值：</p>
<p id="demo"></p>
<script>
  // 创建 Set
  const letters = new Set(["a","b","c"]);
  // 列出所有元素
  let text = "";
  for (const x of letters.values()) {
    text += x + "<br>";
  }
  document.getElementById("demo").innerHTML = text;
</script>
</body>
</html>